Apparatus for manufacturing electric light bulbs



.1. A. HEANY 1,833,488 APPARATUS FOR MANUFACTURING ELECTRIC LIGHT BULBS Nov. 24, 1931.

Original FiledSept. 8 1926 2 Sheets-Sheer Patented Nov. 24, 1931 UNITED STATES PATENT OFFICE JOHN ALLEN HEANY, OF NEW HAVEN, CONNECTIGU '1, ASSIGNOR T SIRIAN LAMP COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF DELAWARE APPARATUS FOR MANUFACTURING ELECTRIC LIGHT BULBS Original application filed September 8, 1926, Serial No. 134,218, and in Canada September 7, 1927. Divided v and this application filed January 23, 1929. Serial No. 334,532.

The invention relates to the manufacture of tipless electric light bulbs and particularly to the manufacture of stems for such bulbs through which the air must be exhausted from the bulb, and by means of which the leadin wires are connected to the lighting filament in the bulb. This application is a division of my copending application Serial No. 134,- 218, filed September 8, 1926. b

In the manufacture of tipless electric light bulbs, it is necessary to exhaust the air through the stem of the bulb and to accomplish this, an exhaust tube is provided which is fused to the stem. Great difliculty has been experienced in fusing the exhaust tubeto the stem, and at the same time maintaining the opening through the tube. To keep the opening through the exhaust tube open, air is sometimes directed through the tube dur- .ing the -fusing process or the tube is sometimes filled with a substance which will crum? ble in the action of heat so that it may be shaken or washed from the tube after the fusing process is completed. One of the objects of this invention is to provide a method of manufacturing tipless electric light bulbs which will maintain the opening through the exhaust tube during the fusing process in a simple and less expensive manner than has been heretofore used. Another object of the invention is to provide an exhaust tube for a stem for a tipless electric light bulb which has been reinforced against a collapse during the fusing process. Another object of the invention is to provide a reinforcing member for the exhaust tube ofa tipless electric light bulb which will prevent the tube from collapsing during the fusing process and which will give with the expansion and contraction of the tube to eliminate undue strains in the glass and possible fracture thereof. Another object of the invention is to-provide a machine in which the improved stem may be manufactured.

Other objects of the invention will be apparent as the description thereof proceeds.

Referring now to the drawings in which an embodiment of my invention has been illust-rated,

Fig. 1 is a front elevation of the stem as the parts are arranged before the fusing process;

Fig. 2 is a front elevation of the stem after the fusing process;

Figs. 3 and 4 are perspective views of two embodiments of the reinforcing member;

Fig. 5 is a front elevation of a stem ada ted {)0 b]: used in a different form of electric llght ul B Fig. 6 is a side view of the stem shown in Fig. 7 is a side elevation of a machine in which the stem may be made,.parts being broken away for purpose of illustration;

Fig. 8 is a front view of the machine shown in Fig. 7;

Fig. 9 is an enlarged sectional elevation of a portion of the machine showing the tubes held therein; and

Fig. 10 is a plan view of the clamps for holding the tubes in position.

Referring now more specifically to the drawings, my improved stem comprises a stem tube 10 into which is inserted an exhaust tube 11 and lead-in wires 12. A reinforcing member 13 comprising a sleeve having a slot 14 extending from end to end on one side thereof is inserted in the tube 11 and may be held in the desired position therein by a slight indentation 15 formed in the side of the exhaust tube 11, or if desired, may be held in position by another method to be hereinafter described. The reinforcing member may be made of any material which is non-fusible at the fusing temperature of glass or it may also be formed of a coil of wire 16, Fig. 4c.

The stem tube 10, exhaust tube 11 and wires 12 may be supported in position shown in Fig, 90

. glass 17 which closes the end of the stem.

1, the tubes heated and the sides of the lower end of the stem tube pressed in fusing the two tubes together and forming a, flat mass of tube and seals the lead-in wires therein. The reinforcing member 13 prevents the glass of the exhaust tube 11 from collapsing when it is heated to the fusing temperature and when the sides of the stem tube are pressed against it.

The stem as shown in Figs. 1 and 2 is-adapted to be used in largeelectric light bulbs, the end18 of the exhaust tube forming a support for the lighting element or filamentlSa of the bulb. After the stem has been completed, as shown in ig. 2, the filament is added and the stem and filament inserted in a bulb 19 having a rounded tipless end, and

the-bulb and stem fused together at 20 in a manner well known to the art.

The stem shown in Figs. 5 and 6 is adapted to be used in small electric lightbulbs which do not need a support for the lighting filament. In this case the exhaust tube 11 is cut off at 21 adjacent the end of the reinforcing member and serves only to provide an opening into the interior bulb through which the air may be exhausted.

The method of manufacturing this improved stem is best carried out by the use of the machine shown in Figs. 7 to 10. A p1urality of these machines are mounted on a spider, one arm 22 of which is shown in Fig. 1. The end of the arm 22 has a sleeve 23 rotatably mounted therein upon the lower end of which is mounted agear 24 and to the upper end of which is attached the standard 25 by means of the set screw 26. Thegear wheel 24 meshes with the gear 27 which is driven by a motor (not shown) which causes the sleeve 23 and the standard 25 to rotate about the axis of. the sleeve 23. A pair of rods 28 are rotatably mounted in lugs 29 and 29a formed integral with the standard 25 and a pair of clamp arms 30 are attached to the upper end of the rods 28; The clamp arms 30 are urged toward each other by spring 31 and are adapted to hold the exhaust tube 11 between their ends, notches being provided therein to accommodate the tube. Spaced a little lower down on the rods 28 are a second pai of clamp arms 33 which are attached to the rods 28, one to each rod, and which are adapted to support the stem tube 10 between the ends thereof,

notches similar to those in the arms 30 being,

provided to fit around the sides of the stem tube. Arms 34 are provided at the bottom of the rods 28, one arm being attached to each rod and a spring 35 is disposed between the arms 34 to urge them apart. The arms 34 may have rounded ends 36 to facilitate the grasping between the fingers, and when the arms are so grasped and squeezed together, the clamp arms 30 and 33 are caused to open so that the tubes 10 and 11 may be inserted or removed therefrom.

A cup 37 is adjust-ably supported from the standard 25 by means of a post 38 and a set screw 39. The cup 37 hasan opening 40 in the bottom -thereof through which the exhaust tube 11 is adapted to fit, the bottom of the cup being larger than the opening 40 to provide a shelf upon whichthe lead-in wires 12 are adapted to be rested before the tubes 10 and 11 are fused together.

A sleeve 41 is slidably mounted within the sleeve 23 by means of a key 41a and is adapted to be reciprocated therein by means of a lever'42 which is pivotedat 43 to an arm 44 integral with the arm 22 of the spider, and the other end of which is bifurcated and engages a spool 45 attached to the lower end of the sleeve 41. A pair of arms 57 having fingers 57a are pivoted to the standard 25 by screws 58 and are pivotally connected to the upper end of the sleeve 41 by screws 60. .When the sleeve 41 is raised by means of the lever 42, the fingers 57a on the arms 57 are brought together against the stem tube 10, pressing the stem tube against the exhaust tube.

A shaft 46 is disposed within the sleeve 41 and is held rigidly with relation to the standard 25 by a clamp 47 integral with the standard 25. The shaft 46 may be raised or lowered in the clamp 47 and held in adjusted position by the set screw 48. A cup 49 is 52 in the shaft 46 passing upwardly through a hole 53 in the cup 49 and up through the tube 11 for the purpose of supporting the reinforcing member 13 therein. The hole 52 in the shaft 46 opens out into a slot 54 and the lower end of the wire 51 is bent outwardly to form a handle 55 by which the wire may be raised and lowered to any desired position with relation to the tube 11. The wire may be held in its adjusted position by means of a thumb screw 56 in the side of the shaft 46.

In the operation of the machine, a flame is directed against the tubes by the burner 61, the tubes, together with the standard being rotated at the same time by the gear 27. When the tubes have been heated to a fusible temperature, the lever 42 may be depressed which brings the arms 57 and'fingers 57a together and fuses the stem tube 10 against the exhaust tube 11 and seals the wires therebetween, forming the flat mass of glass 17. The machine is then stopped and the tubes released by pressing the arms 34, whereupon the finished stems may be removed from the the finished bulb.

Many modifications of the stem shown in the drawings, may be resorted to without departing from the spirit of the invention, and I do not therefore desire to limit myself to the embodiments shown, but to interpret the invention broadly within the scope of the appended claims.

Having described my invention', What I claim and desire to secure by Letters Patent 1s:

1. In a machine for making tipless electric bulbs, means to support an exhaust tube; means to support a stem tube in spaced relation thereto; means to support a reinforcing member in said exhaust tube; and means to fuse said tubes together around said reinforcing member.

2. In a machine for making tipless electric light bulbs, means to support a stem tube; means to support an exhaust tube within and in spaced relation to said stem tube; means to support a reinforcing member in said exhaust tube; means to heat said tubes; means to fuse said tubes together; and means to simultaneously release said tube supporting means.

3. In a machine for making tipless electric light bulbs, means to support a stem tube; means to support an exhaust tube in spaced relation thereto; means to support a reinforcing member within said exhaust tube,

said means comprising a standard; a rod slidably mounted in said standard; means to adjust the extension of said rod; means to secure said rod in adjusted position; and means to fuse said tubes together around said reinforcing member.

4. In a machine for making tipless electric light bulbs, means to support a stem tube;

means to support an exhaust tube in spaced relation thereto; adjustable means to sup-. port a reinforcing member within said exhaust tube; means to rotate said tubes; means to heat said tubes; means to compress said stem tube against said exhaust tube and fiatten said tubes around said reinforcing member whereby said tubes are fused together without closing the opening through said exhaust tube; and means to simultaneously release said stem tube and exhaust tube supporting means. i

5. In a machine for making tipless electric light bulbs, means to support a stem tube; means to support an exhaust tube in spaced relation thereto; means to support lead-in wires between the walls of said tubes; means to support a reinforcing sleeve within said exhaust tube; means to rotate said tubes; means to heat said tubes; means to compress -a portion of said stem tube against said exhaust tube adjacent said reinforcing member whereby said tubes are fused together without closing the opening through said exhaust tube and said lead-in wires are sealed therebetween; and means to simultaneously release said tube supporting means.

In testimony whereof, I afiix my signature.

JOHN ALLEN HEANY. 

